Carburetor



Dec, 11, 1928B J. JUHASZ cARBuREToR Filed Jan, v, 1924 QOR ATTORNEY Patented Dee.. 11, 192.

eure rrs JOHN J' UHASZ, OF NEW lYORK, N. Y.

CARBURETOR.

Application led January 7, 1924. Serial No. 684,765.

The present invention relates to improvements in carburetor-s, more particularly, to multinozzle carburetor-s of the type wherein each nozzle is disposed within an individual y carburetinor chamber, all chambers communicating with a single carburetor outlet, the communication being controlled by a throttle, common to all of said chambers. In carburetors of the general type specified the communications between 4the several carbureting chambers andthe carburetor outlet are usually opened progressively, that is to say the carburetor nozzles are brought into service one after the other or at leastfone group is brought into service after another. In practice serious troubles have been experienced with carburetors of this type for the reason that the throttle does not fit airtight into the carburetor casing, so that at low engine speeds,

when only one of the carburetor nozzles is in service, fuel is drawn from the remaining nozzles and this fuel, not being abley to pass to the carburetor outlet, drops to the bottom of the respective carbureting chamber, to

25. be taken up by the air streams as these chambers are progressively opened. A too rich mixture is thus temporarily obtained when the remaining carburetor nozzles are brought into service, not speaking of the waste of fuel.

The main obje'ct of the present invention is to eliminate this trouble, that is to say to provide a carburetor which furnishes a proper fuel mixture at all times during the operation of the engine. 1

With these and other objects in view, which will more fully appear as the nature of the invention is better understood, the same consists in the combination, arrangement and construction of parts hereinafter described, pointed out in the appended claim and illustrated in the accompanying drawings, it being understood that many changes may be made in the size andproportion of the several parts and details of construction within the scope of the appended claim, without departing from the spirit or sacrificing any of the advantages of the invention.

One of the many possible embodiments of the invention is illustrated in the accompanying drawingsl` in which n Figure l is a top plan view of a carburetor constructed in accordance wth the present invention; Fig. 2 is a sectional elevation of a portion of the carburetor; Fig. 3 is a central vertical section taken through one of the nozzles, on a larger scale; and Fig. 4 is a central vertical section taken through the several tubes of the nozzles. Y

In the drawings, the numeral 10 indicates a carburetor casing, in the side of which is 4formed an opening 11, forming the air inlet to the carbureting chambers 12, of which four are shown in the drawings (Fig. 1), although any other suitable number may be employed according to the requirements. These chambers are 1n the present case in the form of Venturi passages. Into each of these passages pro-jects a fuel nozzle 13, which communicates with a float chamber 14 of any suitable construction, the inlet openings to the nozzles being controlled, for instance, by needle valves 15, although this is not essential. Above the carbureting chambers is disposed a throttle 16, in the present case a cylindrical throttle, for the well known purpose.

Each of the carburetor nozzles comprises a central tube 17, the bore 18 of which is provided with a plurality of sections of varying transverse cross section. The transverse cross sections of these bore sections gradually decrease from the uppermost section to the lowermost, as clearly shown in Fig. 3 of the drawings. The lower end of the tube is provided with a flange 19, on which rests the liange 20 of a tube 21, which encloses the said central tube and is spaced therefrom. The upper open end of the tube 21 is disposed a slight distance below the Vupper end of the central tube 17, onto the 'latter being tted a cap 22, which extends a substantial distance downwards over the tube 21 and is spaced from the latter. The lower open end of the cap is outside the suction area of the tube 17, air flowing into the space between the tube 21 and the said'cap at substantially atmospheric pressure. This air flows into the space between the tubes 17 and 21, and from the latter space into the tube 17, as will be presently described. The flanges `20 and 19 above referred to are disposed in a bore 23 in the carburetor casing, a gasket 24 being interposed between the flange 20 and a shoulder 25 in the said bore, the elements being held in proper position by a screw plug 26, having an aperture 27 in constant communication with the oat chamber 14. The size of the aperture 27 corresponds, preferably, to that of the llowermost bore section of the jet, with which it communicates.

Each central tube 17 is provided with a plurality of holes 28, one associated with each bore section. Through these holes the tube 17 is adapted to communicate with the space between the latter and the tube 21, as will be hereinafter further described. Each of the bores 23 is closed by a screw plug 29,

vthrough which thescrew-threaded stem of a needle valve extends. When the 'plugs 26 and 29 are removed, each of the nozzles may be removed, as a unit, from the carb-uretor casing. y

As above mentioned, the carburetor herein -described includes four carb-uretingchambers, ineach of which is disposed a fuel nozzle. Denoting these nozzles by the numerals I, II., III and IV, it will be observed from Fig. l of the drawings, in which the `central tubes 17 are illustrate-d diagrammatiy with the carburetor outlet, when the throttle is in its closed position, through a minimum opening which is sufficient to permit of a flow of air past the fuel nozzle I into a carbureting chamber so as to furnish combustible mixture for the motor for idling. As the throttle is shifted toward opening position, the carbureting chambers II, III and IV' are brought into action one after the other,

so that, when the throttle is in its fully open position, the four carbureting chambers are in action. In other words, during the opening movement of the throttle the nozzles are brought into service one after another, first the shortest one of the nozzles being brought into service, then the next longer in the series, and so on. The flanges 19 of the several cenltral tubes of the nozzles are disposed in the same horizontal plane. When, therefore, the motor is at standstill the fuel level in the several central tubes, controlled by the iioat in the chamber 14, is at different distances measured from the tops of the said central tubes (see Fig. 4), it being nearest to the top of the central tube of the nozzle I, the distance increasing obviously as the lengths of the nozzles increase. From this it appears that, when the engine is started and the carbureting chamber I is in action, a combustible mixture is formed in the said chamber, the suction of the engine transmitted to the chambers II III and IV while the outlets of such chambers are closed being not sufficient to lift fuel from the nozzles II, III and IV,

as'the fuel level in the tubes 17 of these nozzles, measured from the top of the latter, is too low to permit fuel to be lifted therefrom. IVhen the carbureting chamber II is brought into action, and the suction, due to the increased engine speed, increased, fuel is furnished by the chambers I and II', the suction being not sufficient to lift fuel from the nozzles III and IV, and so on. A proper mixture is thus obtained at all times during the operation of the engine. y

The holes 28 are provided in the central tubes 17 to permit air to be led into the same, the said holes being uncovered progres sively as the level of fuel Within the said tubes is lowered as the suction acting upon the tubes 17 is increased.

Tests, which have been made with the carburetor' herein described, show that the stepped cross-section of the bores of the noz* zlesgive a material reduction in fuel e011-, .-1

sumption, and that this reduction in fuel con sumpt-ion may result from improved atomi zation of the fuel. It appears that the stepped cross-section gives space for the increased volume due to the mixture of fuel with the air which is vented through the holes 28.

It is obvious that, while herein specific noz- .zles have been described, any others may be used in connection with this invention, which lies mainly in the provision of a carburetor having a plurality of independent carbureting chambers, each provided with a fuel nozzle. said nozzles being of different lengths and being brought into action progressively from the shortest to the longest,"as the engine speed increases.

What I claim is A carburetor including a plurality of independent carbureting chambers, a throttle for progressively bringing said carbureting chambers into service, and a. suction controlled nozzle in 'each carbureting chamber, the lower ends of the bores of said nozzles bein@ arranged at the same level and the saidbores being of dierent lengths so as to discharge at different levels, the lengths of the bores increasing in the order in which said carbureting chambers are brought into and maintained in service during the opening movement of said throttle, said bores be ing unobstructed and each bore gradually decreasing in transverse cross-section from its up er end to its lower end.

igned at New York, in the' county of New York, and State of New York, this 19th day of October, A. D. 1923. y

JOHN J UHASZ. 

